People prefer alternative therapies and homeopathy. The majority of side effects are minor like pain, erythema, inflammation and swelling at the injection site. This occurs in about 50% of individuals that receive vaccines. Systemic symptoms specific to each particular vaccine may also occur, including fever, headache, irritability, vomiting, diminished activity and other complications. For instance, the pertussis vaccine is a rare cause of persistent inconsolable crying, high fever and seizures. More serious reactions to vaccines may occur in exceedingly rare circumstances, such as severe allergic reactions, deafness or brain damage. There is an act called the National Childhood Vaccine Injury Act that provides compensation to children that are injured from being vaccinated. In many vaccinations the substance Thimerosal is used which is like Mercury. There has been problems with this linked to allergies and autism. It is currently in much controversy and debate. It is important to always look at the benefits to getting vaccinated then to look at the potential harms of them (Calandrillo, 2004).